Vehicle display device

ABSTRACT

A vehicle display device includes a display control unit that is configured to: display markers in positions, on a display unit, corresponding to future positions of a host vehicle which are acquired from an autonomous driving control unit that autonomously drives the host vehicle, and move display positions of the markers on the display unit in accordance with travel of the host vehicle and toward a reference position on the display unit corresponding to the host vehicle.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application of U.S. patent application Ser. No.17/301,721, filed Apr. 12, 2021, which is a continuation application ofU.S. patent application Ser. No. 16/831,230, filed Mar. 26, 2020, whichis based on and claims priority under 35 USC 119 from Japanese PatentApplication No. 2019-064664 filed on Mar. 28, 2019, the disclosures ofwhich are incorporated by reference herein.

BACKGROUND

Technical Field

The present disclosure relates to a vehicle display device.

Related Art

Japanese Patent Application Laid-open (JP-A) No. H08-178679 discloses atechnology that detects the traveling state of a vehicle, calculates afuture projected trajectory of the vehicle on the basis of the detectedtraveling state, and displays the projected trajectory on a head-updisplay device. In this technology, the projected trajectory isdisplayed as a bird's eye view in which a group of points are arrayed atpredetermined intervals on a curve representing the projected trajectoryof the center of gravity of the vehicle and in which boxes havingsubstantially the same width as the width of the vehicle are arrangedwith the center of gravity being matched to each of the group of points.

The technology disclosed in JP-A No. H08-178679 presupposes displayinginformation on a superimposed (augmented reality, or AR) type head-updisplay that entirely covers the forward field of view of an occupant inthe front seat of the vehicle, but the optical system for realizing sucha large head-up display is extremely difficult to construct and at thepresent time is not realistic. On the other hand, if the technologydisclosed in JP-A No. H08-178679 is applied to display information on asmall display unit, such as a small head-up display whose display rangeis part of the forward field of view of the occupant or a display in aninstrument panel, it would become difficult for the driver tointuitively grasp that the information being displayed on the displayunit corresponds to the actual foreground the driver is seeing, so thistechnology has room for improvement.

SUMMARY

The present disclosure has been devised in consideration of the abovecircumstances and provides a vehicle display device which, even in thecase of displaying information on a small display unit that does notwidely cover the forward field of view of an occupant, allows theoccupant to intuitively grasp that the display information correspondsto the actual foreground.

One aspect of the disclosure is a vehicle display device including adisplay control unit that is configured to display markers in positions,on a display unit, corresponding to future positions of a host vehiclewhich are acquired from an autonomous driving control unit thatautonomously drives the host vehicle, and move display positions of themarkers on the display unit in accordance with travel of the hostvehicle and toward a reference position on the display unitcorresponding to the host vehicle.

In the aspect, the display control unit moves the display positions, onthe display unit, of the markers that is displayed in positions on thedisplay unit corresponding to the future positions of the host vehicle,toward the reference position on the display unit corresponding to thehost vehicle, in accordance with the travel of the host vehicle. Becauseof this, the display positions of the markers move as if synchronouslywith the travel of the host vehicle, so even in the case of displayinginformation on a small display unit that does not cover the forwardfield of view of the occupant, the display control unit allows theoccupant to intuitively grasp that the display information correspondsto the actual foreground. Furthermore, the dynamic flow of the markersserves as an appropriate stimulant and helps the occupant maintain themotivation to continuously monitor the travel of the host vehicle.

In the aspect, the display control unit may be configured to move thedisplay positions of the markers on the display unit toward thereference position on the display unit, by switching the futurepositions at which the markers are displayed so that time differencesbetween the future positions and the current time become smaller as timeelapses.

The moving of the display positions of the markers on the display unittoward the reference position on the display unit may be realized byswitching the future positions at which the display control unitdisplays the markers so that the time differences of the futurepositions from the current time become smaller as time elapses asdescribed above for example. Because of this, the display positions ofthe markers on the display unit may be moved by the simple process ofswitching the future positions at which the display control unitdisplays the markers.

In the aspect, the display control unit may be configured to display themarkers in plural positions on the display unit corresponding to pluralfuture positions of the host vehicle each having a time difference thatdiffers from the current time by a predetermined amount of time.

In this configuration, the time differences, from the current time, ofthe plural future positions at which the display control unit displaysthe markers differ a predetermined amount of time each. Therefore, thedisplay control unit allows the occupant to intuitively grasp, from thedisplay intervals between the plural markers, changes in the behavior ofthe host vehicle in the time axis direction including acceleration anddeceleration of the host vehicle.

In the aspect, the display control unit may be configured to display, onthe display unit, a band-like trajectory line having a width directionthat is aligned with a vehicle width direction of the host vehicle,having a length direction that is aligned with an array of the futurepositions of the host vehicle, and which contains the markers.

In this configuration, the display control unit displays the band-liketrajectory line, and the trajectory line has its width direction alignedwith the vehicle width direction of the host vehicle, has its lengthdirection aligned with the array of future positions of the hostvehicle, and contains the markers. Therefore, it allows the occupant tointuitively grasp, from the direction in which the trajectory lineextends, the advancing position of the host vehicle.

In the aspect, the display control unit may be configured to display, onthe display unit, road width lines that simulate boundary lines of alane in which the host vehicle is traveling.

In this configuration, the display control unit displays the road widthlines that simulate the boundary lines of the lane in which the hostvehicle is traveling, so it allows the occupant to more intuitivelygrasp that the display information corresponds to the actual foreground.

In the aspect, the display control unit may be configured to, in a casein which a time headway setting for autonomous driving control of thehost vehicle has been changed, display, on the display unit, headwaysetting lines according to a time headway that has been set.

In this configuration, in a case in which the time headway setting inthe autonomous driving mode has been changed, the display control unitdisplays the headway setting lines according to the time headway thathas been set, so the vehicle display device allows the occupant to graspthe time headway setting. The markers pertaining to this disclosure areindicators whose display positions on the display unit move, soconfusion between the markers and the headway setting lines may beavoided.

In the aspect, the display unit may include a head-up display having adisplay range that is part of a forward field of view of an occupant ofthe host vehicle, a display provided in an instrument panel of the hostvehicle, or a combination thereof.

In this configuration, the display unit is a small display that does notwidely cover the forward field of view of the occupant, namely, ahead-up display whose display range is part of the forward field of viewof the occupant of the host vehicle or a display provided in theinstrument panel of the host vehicle. Because of this, the vehicledisplay device may employ a configuration that is easy to implement asthe display unit and allows the occupant to intuitively grasp that theinformation displayed on the display corresponds to the actualforeground.

Another aspect of the disclosure is a vehicle display control methodincluding: displaying markers in positions, on a display unit,corresponding to future positions of a host vehicle acquired which arefrom an autonomous driving control unit that autonomously drives thehost vehicle; and moving display positions of the markers on the displayunit in accordance with travel of the host vehicle and toward areference position on the display unit corresponding to the hostvehicle.

Yet another aspect of the disclosure is a non-transitory storage mediumstoring a program that causes a computer to execute a vehicle displaycontrol process, the vehicle display control process including:displaying markers in positions, on a display unit, corresponding tofuture positions of a host vehicle which are acquired from an autonomousdriving control unit that autonomously drives the host vehicle; andmoving display positions of the markers on the display unit inaccordance with travel of the host vehicle and toward a referenceposition on the display unit corresponding to the host vehicle.

The vehicle display device of this disclosure allows, even in the caseof displaying information on a small display unit that does not widelycover the forward field of view of an occupant, the occupant tointuitively grasp that the display information corresponds to the actualforeground.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the general configuration of anin-vehicle system pertaining to an exemplary embodiment;

FIG. 2 is a drawing illustrating an example of the display range of aHUD;

FIG. 3 is a flowchart illustrating a display control process;

FIG. 4A and FIG. 4B are drawings illustrating examples of normal imagesdisplayed on the HUD and a meter display, respectively;

FIG. 5A is a drawing illustrating an example of a first-personsingle-lane display image displayed on the HUD;

FIG. 5B is a drawing illustrating an example of a third-personmulti-lane display image displayed on the meter display;

FIG. 6 is a drawing illustrating an example of the first-personsingle-lane display image displayed on the HUD when traveling on astraight road;

FIG. 7 is a drawing illustrating an example of the first-personsingle-lane display image displayed on the HUD when coming to a curve inthe road;

FIG. 8 is a drawing illustrating an example of the first-personsingle-lane display image displayed on the HUD when the host vehiclechanges lanes;

FIG. 9 is a drawing illustrating an example of the first-personsingle-lane display image displayed on the HUD when coming to a fork inthe road;

FIG. 10 is a conceptual drawing for describing a process of selectingfuture positions at which to display markers;

FIG. 11 is a drawing for describing a process of changing the displayposition of the image on the HUD in accordance with the steering angleof the steering system;

FIG. 12 is a drawing for describing the process of changing the displayposition of the image on the HUD in accordance with the steering angleof the steering system;

FIG. 13 is a drawing illustrating an example of a situation requiringdriver intervention during autonomous driving; and

FIG. 14 is a drawing illustrating another example of a situationrequiring driver intervention during autonomous driving.

DETAILED DESCRIPTION

An exemplary embodiment of the disclosure will be described in detailbelow with reference to the drawings. An in-vehicle system 10illustrated in FIG. 1 is equipped with a communication bus 12, andconnected to the communication bus 12 are a surrounding conditionsacquisition device group 14, a vehicle traveling state detection sensorgroup 26, an autonomous driving electronic control unit (ECU) 34, and adisplay control ECU 42. It will be noted that FIG. 1 illustrates onlypart of the in-vehicle system 10. Furthermore, below, the vehicle inwhich the in-vehicle system 10 is installed is called the host vehicle.

The surrounding conditions acquisition device group 14 includes, asdevices that acquire information about the conditions of the environmentaround the host vehicle, a global positioning system (GPS) device 16, anin-vehicle communicator 18, a navigation system 20, a radar device 22,and a camera 24.

The GPS device 16 receives GPS signals from plural GPS satellites tolocate the position of the host vehicle. The positioning precision ofthe GPS device 16 becomes better as the number of receivable GPS signalsincreases. The in-vehicle communicator 18 is a communication device thatperforms at least one of vehicle-to-vehicle communication with othervehicles and vehicle-to-roadside communication with roadside units. Thenavigation system 20 includes a map information storage unit 20A thatstores map information, and the navigation system 20 performs a processthat displays the host vehicle's position on a map and providesdirections to the host vehicle's destination on the basis of theposition information obtained from the GPS device 16 and the mapinformation stored in the map information storage unit 20A.

The radar device 22 includes plural radar devices with mutuallydifferent detection ranges, detects objects such as pedestrians andother vehicles in the area around the host vehicle as point groupinformation, and acquires the positions and velocities of the detectedobjects relative to the host vehicle. Furthermore, the radar device 22has a built-in processor that processes the detections results of theobjects in the area around the host vehicle. The processor excludes,from its monitoring targets, noise and roadside objects such asguardrails on the basis of changes in the positions and velocities,relative to the host vehicle, of individual objects included in the mostrecent results of multiple detections, and tracks and monitors specificobjects such as pedestrians and other vehicles as monitoring targetobjects. Additionally, the radar device 22 outputs information such asthe positions and velocities of individual monitoring target objectsrelative to the host vehicle. The camera 24 captures, with pluralcameras, images of the area around the host vehicle and outputs theimages it has captured.

Furthermore, the vehicle traveling state detection sensor group 26includes, as plural sensors that acquire information about the travelingstate of the host vehicle, a steering angle sensor 28 that detects thesteering angle of the host vehicle, a vehicle speed sensor 30 thatdetects the traveling speed of the host vehicle, and an accelerationsensor 32 that detects acceleration applied to the host vehicle.

Connected to the autonomous driving ECU 34 are a throttle actuator 36that changes the throttle position of the host vehicle and a brakeactuator 38 that changes the braking force generated by the brakingsystem of the host vehicle. Also connected to the autonomous driving ECU34 is a steering actuator 40 that changes the amount of steering by thesteering system of the host vehicle.

The autonomous driving ECU 34 includes a central processing unit (CPU),a memory including a read-only memory (ROM) and a random-access memory(RAM), a nonvolatile storage unit such as a hard disk drive (HDD) or asolid state drive (SSD), and a communication interface. Autonomousdriving software (program) is stored in the storage unit. When anautonomous driving mode is selected, the CPU executes the autonomousdriving software (program), whereby the autonomous driving ECU 34performs an autonomous driving process that allows the host vehicle totravel autonomously without driving input from the occupant of the hostvehicle. The autonomous driving process is a process that judges theconditions of the host vehicle and its surroundings and controls thethrottle actuator 36, the brake actuator 38, and the steering actuator40 on the basis of the information obtained from the surroundingconditions acquisition device group 14 and the vehicle traveling statedetection sensor group 26.

In the exemplary embodiment, the level of autonomous driving performedby the autonomous driving ECU 34 is Level 2 or Level 3. Level 2 or Level3 autonomous driving requires the driver to monitor the autonomousdriving by the autonomous driving ECU 34 and intervene as needed inanticipation of cases that fall outside the controllable scope of theautonomous driving ECU 34 or actions for which the autonomous drivingECU 34 is not fit due to sensor misdetection, non-detection, or failure.

The display control ECU 42 includes a CPU 44, a memory 46 including aROM and a RAM, a nonvolatile storage unit 48 such as an HDD or an SSD,and a communication interface 50. The CPU 44, the memory 46, the storageunit 48, and the communication interface 50 are communicably connectedto each other via an internal bus 52. A display control program 54 isstored in the storage unit 48. The display control ECU 42 executes alater-described display control process as a result of the displaycontrol program 54 being read out from the storage unit 48 and loaded tothe memory 46, and then the display control program 54 that has beenloaded to the memory 46 being executed by the CPU 44.

Connected to the display control ECU 42 are a head-up display(hereinafter called the HUD) 56 and a meter display 58. The HUD 56pertaining to the exemplary embodiment is a small HUD whose displayrange is part of the forward field of view of the occupant of the hostvehicle (forms an image in the lower foreground) by reflection on thewindshield glass, for example, as illustrated in FIG. 2 where referencesign 60 denotes the display range. Furthermore, the meter display 58 isa display provided in the instrument panel of the host vehicle. Thedisplay control ECU 42 controls the display of information on the HUD 56and the meter display 58.

The autonomous driving ECU 34 is an example of an autonomous drivingcontrol unit, and the display control ECU 42 is an example of a displaycontrol unit. Furthermore, the HUD 56 and the meter display 58 areexamples of a display unit.

Next, the operation of the present embodiment will be described. Whilethe autonomous driving ECU 34 is performing autonomous driving, thedriver needs to continuously pay attention to the behavior of the hostvehicle and surrounding traffic conditions, continuously grasp thebehavior of the host vehicle and surrounding traffic conditions, andremain alert and prepared to act when intervention is necessary.However, if the host vehicle conveys, moment by moment as is to thedriver, the surrounding conditions captured by the sensors, theexcessive conveyance of information would increase the burden on thedriver and so would defeat the purpose of autonomous driving, which isto alleviate the burden of driving.

Furthermore, in cases in which the host vehicle detects a need of somesort and begins non-routine driving operations, such as a fork in or amerging of the lane, or a lane change, the host vehicle may alert thedriver. However, in cases in which, for example, the host vehicle isunable to detect an obstacle that has suddenly appeared on the road andcontinues routine driving as is even though it should avoid theobstacle, the host vehicle may not alert the driver because it does notcontemplate demanding the driver's attention in the first place.

In view of these problems, the display control ECU 42 performs thedisplay control process illustrated in FIG. 3 . In step 100 of thedisplay control process, the display control ECU 42 determines whetheror not autonomous driving is being performed by the autonomous drivingECU 34.

In a case in which the determination of step 100 is NO, the displaycontrol ECU 42 moves to step 120. In step 120, the display control ECU42 displays normal images on the HUD 56 and the meter display 58. FIG.4A illustrates an example of the normal image displayed on the HUD 56,and FIG. 4B illustrates an example of the normal image displayed on themeter display 58.

In a case in which autonomous driving is being performed by theautonomous driving ECU 34, the determination of step 100 is YES and thedisplay control ECU 42 moves to step 102. In step 102, the displaycontrol ECU 42 acquires, from the autonomous driving ECU 34, informationon the lanes being identified by the autonomous driving ECU 34. The laneinformation includes information relating to the host vehicle's lane inwhich the host vehicle is traveling (i.e., information such as whetherthe lane is straight or curved) and information relating to adjacentlanes adjacent to the right and left of the host vehicle's lane (i.e.,information on whether or not there are adjacent lanes). Then, on thebasis of the lane information acquired from the autonomous driving ECU34, the display control ECU 42 generates, as images including road widthlines 62 that simulates lane boundary lines, a first-person single-lanedisplay image such as illustrated in FIG. 5A as an example and athird-person multi-lane display image such as illustrated in FIG. 5B asan example.

The first-person single-lane display image is an image close to what thedriver sees in the forward direction through the windshield glass of thehost vehicle, and lanes adjacent to the right and left of the hostvehicle's lane are excluded from the display target. The first-personsingle-lane display image is an image in which the host vehicle's laneis displayed as large as possible and in which intrusiveness isminimized by not displaying information that is not important formonitoring travel. Various indicators described later are displayedlarge and conspicuously on the first-person single-lane display image.

The third-person multi-lane display image is an image in which the hostvehicle is seen in a bird's eye view from above and behind and whosedisplay targets are the host vehicle's lane and the lanes adjacentthereto on the right and left. Lanes that do not exist become excludedfrom the display targets, so in typical conditions there are a maximumof three lanes displayed in the third-person multi-lane display image.However, the third-person multi-lane display image is not limited to amaximum of three lanes for the ease of understanding transient statesand the like accompanying forks and merges. In the third-personmulti-lane display image, the host vehicle is displayed as an icon 64.The third-person multi-lane display image may display a situation inwhich, for example, there is another vehicle approaching and the hostvehicle defers changing lanes, as in a situation in which the hostvehicle is about to change lanes but there is another vehicleapproaching from the rear right or the rear left and so the host vehicledefers changing lanes until the other vehicle passes and then the hostvehicle changes lanes.

In the first-person single-lane display image and the third-personmulti-lane display image, the road width lines 62 that simulates laneboundary lines are displayed, so, for example, when the host vehiclecomes to a curve in the road on which it is traveling, the road widthlines 62 change from the display illustrated in FIG. 6 to the displayillustrated in FIG. 7 , and when the host vehicle comes to a fork in theroad on which it is traveling, the road width lines 62 change from thedisplay illustrated in FIG. 6 to the display illustrated in FIG. 9 .This allows the driver to understand that the first-person single-lanedisplay image and the third-person multi-lane display image are roaddiagrams having a contrasting relationship of similarity reduction withthe actual scene (i.e., a perspective representation of the laneboundary lines). Furthermore, when the host vehicle is about to changelanes, as illustrated in FIG. 8 , markers 66 and a trajectory line 68described later change while the road width lines 62 remain unchanged,whereby the driver understands that the host vehicle is about to changelanes.

In step 104, the display control ECU 42 acquires an array of coordinatesof future positions of the host vehicle from the autonomous driving ECU34 and selects future positions at which to display markers 66 (see FIG.5 , etc.). As an example, a case will be described in whichcommunication is performed every 100 milliseconds between the displaycontrol ECU 42 and the autonomous driving ECU 34 and in which, with eachcommunication, as illustrated in FIG. 10 , an array of coordinates offuture positions of the host vehicle with a finite number in 100millisecond-increments (e.g., 50 coordinates=5 seconds later) istransmitted from the autonomous driving ECU 34 to the display controlECU 42.

At time t0, the display control ECU 42 selects the current position ofthe host vehicle as an origin n0, selects the nine coordinates n1 to n9from the front as future positions at which to not display a marker 66,and selects the tenth coordinate n10 as a future position at which todisplay a marker 66. In the same way, the display control ECU 42 selectscoordinates n11 to n19 as future positions at which to not display amarker 66 and selects coordinate n20 as a future position at which todisplay a marker 66. Because of this, an array of markers 66 at 1-secondintervals with respect to the array of coordinates of future positionsreceived from the autonomous driving ECU 34 is generated.

Furthermore, at time t1 100 milliseconds later, the host vehiclegenerally moves to the position of coordinate n1 that was received attime t0, and the display control ECU 42 generates an array of newmarkers 66 using as a reference the new position of the host vehicle. Atthat time, the display control ECU 42 keeps the display/hide attributesin regard to each of the coordinates that were received at time t0, sothat the display control ECU 42 selects coordinates n1 to n8 as futurepositions at which to hide or not display a marker 66, selectscoordinate n9 as a future position at which to display a marker 66,selects coordinates n10 to n18 as future positions at which to notdisplay a marker 66, and selects coordinate n19 as a future position atwhich to display a marker 66. In other words, the display control unit42 switches the future positions at which it displays the markers 66 sothat time differences, from the current time, of the future positions atwhich it displays the markers 66 become smaller as time elapses (e.g.,time t0→time t1). As a result, at time t1 an array of markers 66 whosephases have moved 100 milliseconds' worth toward the host vehiclecompared to time t0 is generated.

In step 106, the display control ECU 42, based on the results of havingselected future positions at which to display the markers 66 in step104, converts the coordinates of the future positions at which todisplay the markers 66 to coordinates on the first-person single-lanedisplay image illustrated in FIG. 5A and displays the markers 66 on theconverted coordinates on the first-person single-lane display image.Furthermore, the display control ECU 42 converts the coordinates of thefuture positions at which to display the markers 66 to coordinates onthe third-person multi-lane display image illustrated in FIG. 5B anddisplays the markers 66 on the converted coordinates on the third-personmulti-lane display image.

Through the processes of steps 104 and 106, on the first-personsingle-lane display image and the third-person multi-lane display imagethe markers 66 are displayed in positions corresponding to the futurepositions of the host vehicle and the array of markers 66 advancesforward (i.e., moves downward on the displays) in accordance with thetravel of the host vehicle and toward the reference positioncorresponding to the host vehicle. This results in a display in whichthe array of markers 66 placed on the road every fixed amount of time(e.g., every 1 second) flows along. Because of this, the driver isallowed to intuitively grasp that the first-person single-lane displayimage and the third-person multi-lane display image correspond to theactual foreground.

In periods in which the display control ECU 42 is not communicating withthe autonomous driving ECU 34 (e.g., the period between time t0 and timet1), it is desired that the display control ECU 42 calculate the displaypositions of the markers 66 by extrapolation, for example, and displaythe markers 66. This results in a continuous motion in which the markers66 are animated, enabling in a higher-quality, smoother display.

In step 108, the display control ECU 42 displays on the first-personsingle-lane display image and the third-person multi-lane display imagea band-like trajectory line 68 whose width direction is aligned with thevehicle width direction of the host vehicle, whose length direction isaligned with the array of future positions of the host vehicle, andwhich contains the array of markers 66 (see FIG. 5A and FIG. 5B). In thefirst-person single-lane display image and the third-person multi-lanedisplay image, the direction in which the band-like trajectory line 68extends represents the direction in which the host vehicle advances,which allows the driver to intuitively grasp the advancing position ofthe host vehicle.

Furthermore, the band-like trajectory line 68 that extends in thedirection in which the host vehicle advances is understood by the driveras a representation that resembles rails laid on top of the road, andthe markers 66 placed every fixed amount of time are understood by thedriver as representations that resemble ties on a railroad track. Inthis way, the representation formed by the markers 66 and the trajectoryline 68 forms a mental model with a sense of familiarity to many people,so it allows the driver to intuitively recognize that it is an advancedisplay of future times to which the host vehicle will travel from now.

In step 112, the display control ECU 42 determines whether or not aheadway (inter-vehicle) setting with respect to autonomous driving isbeing changed. If the headway setting is being changed, thedetermination of step 112 is YES and the display control ECU 42 moves tostep 114. In step 114, the display control ECU 42 displays, on thefirst-person single-lane display image and the third-person multi-lanedisplay image, headway setting lines 70 representing the set timeheadway (the number of the headway setting lines 70 changes inaccordance with the set time headway) (see FIG. 5A and FIG. 5B).

In this way, when the display control ECU 42 displays the headwaysetting lines 70, it may allow the driver to grasp the set time headway.Furthermore, in the exemplary embodiment, the headway setting lines 70are stationary on the first-person single-lane display image and thethird-person multi-lane display image. In contrast, the markers 66 aremarkers whose display positions move as the host vehicle travels, soconfusion between the markers 66 and the headway setting lines 70 may beavoided.

In a case in which the headway setting is not being changed, thedetermination of step 112 is NO and step 114 is skipped. In this case,the headway setting lines 70 are not displayed on the first-personsingle-lane display image and the third-person multi-lane display image.

In step 116, the display control ECU 42 displays the first-personsingle-lane display image on the HUD 56 as illustrated in FIG. 5A. Indisplaying the image on the HUD 56, the display control ECU 42 performsa process that changes the display position of the image on the HUD 56in accordance with the steering angle of the steering system.

Namely, first, the display control ECU 42 acquires the steering angle ofthe steering system detected by the steering angle sensor 28. Then, ifthe steering angle of the steering system is 0, the display control ECU42 displays the first-person single-lane display image on the HUD 56 sothat, as illustrated in FIG. 11 as an example, the image center of thefirst-person single-lane display image displayed on the HUD 56 coincideswith a center CL of the display range of the HUD 56.

However, in a case in which the steering angle of the steering system isnot 0, the display control ECU 42 displays the first-person single-lanedisplay image on the HUD 56 so that, as illustrated in FIG. 12 as anexample, the image center of the first-person single-lane display imagedisplayed on the HUD 56 is offset a predetermined offset amountaccording to the steering angle amount in the steering direction(rightward or leftward) with respect to the center CL of the displayrange of the HUD 56.

As an example, FIG. 12 illustrates the image center of the first-personsingle-lane display image being offset in the rightward direction withrespect to the center CL of the display range of the HUD 56. This allowsthe occupant to always feel that the host vehicle is in an appropriateposition in the lane, without the image displayed on the HUD 56 shiftingto the outside of the corner, in a case in which the road on which thehost vehicle is traveling curves.

In the next step 118, the display control ECU 42 displays thethird-person multi-lane display image on the meter display 58 asillustrated also in FIG. 5B. When the display control ECU 42 performsthe process of step 118, it returns to step 100 and repeats step 102 tostep 118 while the determination of step 100 is YES.

In Level 2 or Level 3 autonomous driving, situations requiring theintervention of the driver may arise. As an example, FIG. 13 illustratesa situation in which the host vehicle is about to change lanes to theleft lane adjacent to the left side of the host vehicle's lane despitethe fact that there is a bus traveling in the left lane (i.e., asituation in which the host vehicle is not recognizing that the busposes a danger to changing lanes). Here, it is desired that the driverintervene to abort the lane change. Even in a case such as this, thedisplay control ECU 42 displays the markers 66, the trajectory line 68,and the road width lines 62 on the HUD 56 so that it may promptly makethe driver aware that the host vehicle is about to change lanes to theleft lane. Then, the driver may recognize that the bus poses a danger tochanging lanes and may intervene to abort the lane change, without thehost vehicle issuing a special alert.

Furthermore, as an example, FIG. 14 illustrates a situation in which thehost vehicle is about to proceed straight despite the fact that the hostvehicle's lane is blocked ahead by a lane closure (i.e., a situation inwhich the host vehicle does not recognize that the host vehicle's laneis blocked ahead). Here, it is desired that the driver intervene tochange lanes. Even in a case such as this, the display control ECU 42displays the markers 66, the trajectory line 68, and the road widthlines 62 on the HUD 56 so that it may promptly make the driver away thatthe host vehicle is about to proceed straight. Then, the driver mayrecognize that the host vehicle's lane in which the host vehicle isabout to proceed straight is blocked ahead and may intervene to changelanes, without the host vehicle issuing a special alert.

As described above, in the exemplary embodiment, the display control ECU42 displays the markers 66 in positions on the HUD 56 and the meterdisplay 58 corresponding to the future positions of the host vehicleacquired from the autonomous driving ECU 34 that autonomously drives thehost vehicle, and the display control ECU 42 moves the display positionsof the markers 66 on the HUD 56 and the meter display 58 in accordancewith the travel of the host vehicle and toward the reference position onthe HUD 56 and the meter display 58 corresponding to the host vehicle.Because of this, the display positions of the markers 66 move as ifsynchronously with the travel of the host vehicle, so even in the caseof displaying information on the small HUD 56, which does not widelycover the forward field of view of the occupant, and the meter display58, the display control ECU 42 allows the driver to intuitively graspthat the display information corresponds to the actual foreground.

Furthermore, in the exemplary embodiment, the display control ECU 42moves the display positions of the markers 66 on the HUD 56 and on themeter display 58 toward the reference position on the HUD 56 and themeter display 58 by switching the future positions of the host vehicleat which it displays the markers 66 so that the time differences of thefuture positions of the host vehicle from the current time becomesmaller as time elapses. Because of this, the display positions of themarkers 66 on the HUD 56 and the meter display 58 may be moved by thesimple process of switching the future positions at which the displaycontrol ECU 42 displays the markers 66.

Furthermore, in the exemplary embodiment, the display control ECU 42displays the markers 66 in plural positions on the HUD 56 and the meterdisplay 58 corresponding to plural future positions of the host vehiclewhose time differences from the current time differ a predeterminedamount of time each. This allows the driver to intuitively grasp, fromthe display intervals between the plural markers 66, changes in thebehavior of the host vehicle in the time axis direction includingacceleration and deceleration of the vehicle.

Furthermore, in the exemplary embodiment, the display control ECU 42displays on the HUD 56 and the meter display 58 the band-like trajectoryline 68 whose width direction is aligned with the vehicle widthdirection of the host vehicle, whose length direction is aligned withthe array of future positions of the host vehicle, and which containsthe array of markers 66. This allows the driver to intuitively grasp,from the direction in which the trajectory line 68 extends, theadvancing position of the host vehicle.

Furthermore, in the exemplary embodiment, the display control ECU 42displays on the HUD 56 and the meter display 58 the road width lines 62that simulate the boundary lines of the lane in which the host vehicleis traveling. This allows the driver to more intuitively grasp that thedisplay information corresponds to the actual foreground.

Furthermore, in the exemplary embodiment, in a case in which the timeheadway has been changed, the display control ECU 42 displays on the HUD56 and the meter display 58 the headway setting lines 70 according tothe time headway that has been set, so the driver may grasp the timeheadway.

Although in the exemplary embodiment the markers 66 are configured tohave the shape of a rhomboid, the markers 66 are not limited to this andmay also be configured to have another shape, such as a circular shapeor an elliptical shape.

Furthermore, although in the above description the autonomous drivingECU 34 is configured to perform Level 2 or Level 3 autonomous driving,the disclosure is not limited to this and may also be applied to aconfiguration that performs Level 4 or Level 5 autonomous driving.Driver intervention is unnecessary in Level 4 and higher autonomousdriving, but by performing the display pertaining to this disclosure,the occupant of the vehicle is allowed to intuitively grasp thatautonomous driving is functioning normally and be given a sense ofsecurity.

Furthermore, although in the above description the display control ECU42 is configured to perform the display pertaining to the disclosure(display such as the markers 66, the trajectory line 68, and the roadwidth lines 62) with respect to each of the HUD 56 and the meter display58, the display control ECU 42 is not limited to this and may also beconfigured to perform the display pertaining to the disclosure withrespect to either one of the HUD 56 and the meter display 58 and performnormal display (e.g., the display in FIG. 4A or FIG. 4B) with respect tothe other display.

The display control program 54 of this disclosure may also be stored inan external server and loaded to the memory via a network. Furthermore,the display control program 54 may also be stored in a non-transitorystorage medium such as a digital versatile disk (DVD) and loaded to thememory via a storage medium reading device.

What is claimed is:
 1. A vehicle display device comprising: a storageunit having a display control program stored thereon; a memory havingthe display control program loaded thereon; and a central processingunit (CPU) that is coupled to the memory to execute the display controlprogram to: acquire coordinates corresponding to future positions of ahost vehicle from an autonomous driving control unit that autonomouslydrives the host vehicle, generate a band-like trajectory line; anddisplay the band-like trajectory line in a position, on a first displayunit, corresponding to the future positions of the host vehicle based onthe acquired coordinates, wherein a width of the band-like trajectoryline displayed on the first display unit is narrower than a width of alane in which the host vehicle is traveling and a width of the hostvehicle in the first display.
 2. The vehicle display device according toclaim 1, wherein the CPU executes the display control program to move adisplay position of the band-like trajectory line on the first displayunit in accordance with travel of the host vehicle and toward areference position on the first display unit corresponding to the hostvehicle.
 3. The vehicle display device according to claim 1, wherein theCPU executes the display control program to select a coordinatecorresponding to a future position to be displayed on the first displayunit from the acquired coordinates.
 4. The vehicle display deviceaccording to claim 3, wherein the CPU executes the display controlprogram to convert the selected coordinate into a coordinate on thefirst display unit.
 5. The vehicle display device according to claim 1,wherein the CPU executes the display control program to display, on thefirst display unit, an image in which a first-person perspective imageand the band-like trajectory line are combined, the first-personperspective image being an image expressing a perspective of a driver ofthe host vehicle.
 6. The vehicle display device according to claim 1,wherein the first display unit comprises a head-up display having adisplay range that is part of a forward field of view of an occupant ofthe host vehicle.
 7. The vehicle display device according to claim 1,wherein the CPU executes the display control program to display, on asecond display unit that is separate from the first display unit, animage in which a third-person perspective image and the band-liketrajectory line are combined, the third-person perspective image beingan image expressing a perspective of a bird's eye view seen from aboveand behind the host vehicle.
 8. The vehicle display device according toclaim 7, wherein the second display unit comprises a display provided inan instrument panel of the host vehicle.
 9. The vehicle display deviceaccording to claim 1, wherein the CPU executes the display controlprogram to display, on the first display unit, road width lines thatsimulate boundary lines of a lane in which the host vehicle istraveling.
 10. The vehicle display device according to claim 1, whereinthe CPU executes the display control program to, in a case in which atime headway setting for autonomous driving control of the host vehiclehas been changed, display, on the first display unit, headway settinglines according to a time headway that has been set.
 11. The vehicledisplay device according to claim 10, wherein the CPU executes thedisplay control program to display the headway setting lines stationaryon a display screen of the first display unit.
 12. The vehicle displaydevice according to claim 10, wherein the CPU executes the displaycontrol program not to display the headway setting lines stationary onthe first display unit in a case in which the time headway setting forautonomous driving control of the host vehicle is not changed.
 13. Avehicle display control method comprising: acquiring coordinatescorresponding to future positions of a host vehicle from an autonomousdriving control unit that autonomously drives the host vehicle;generating a band-like trajectory line; and displaying the band-liketrajectory line in a position, on a first display unit, corresponding tothe future positions of the host vehicle based on the acquiredcoordinates; wherein a width of the band-like trajectory line displayedon the first display unit is narrower than a width of a lane in whichthe host vehicle is traveling and a width of the host vehicle in thefirst display.
 14. A non-transitory storage medium storing a programthat causes a computer to execute a vehicle display control process, thevehicle display control process comprising: acquiring coordinatescorresponding to future positions of a host vehicle from an autonomousdriving control unit that autonomously drives the host vehicle;generating a a band-like trajectory line; and displaying the band-liketrajectory line in a position, on a first display unit, corresponding tothe future positions of the host vehicle based on the acquiredcoordinates; wherein a width of the band-like trajectory line displayedon the first display unit is narrower than a width of a lane in whichthe host vehicle is traveling and a width of the host vehicle in thefirst display.